Many people have bought parts of the moon for millions of dollars but is it worth more? Of course it is!
If you owned the known space around us you would have more money than the Government can give you! The problem with people "owning" space is that what the things people might do with it would be crazy, reckless and even dangerous. Lets say Elon Musk owned space would he take care of it or send a million teslas into orbit? But lets say someone with more political power owned space like Donald Trump, we've already heard about Donald Trump's space army, if he owned space, he would be able to complete his plan without anyone being able to stop him as he owns space, he would be able to rain terror on any country that he pleases.
What I'm trying to say that space shouldn't be for sale (like Antarctica) because you never know who is buying it and what they will do with it.